on Mac OS, YMMV on linux, but i think syntax is same…

1. connect directly into the managment port with a straight ethernet cable
2. find the MAC address for the APC PDU management interface, usually a sticker or paper QC checklist taped to the device.
3. $ sudo arp -s 192.168.1.X 00:c0:b7:fc:XX:XX
   •this creates a static entry in the arp table telling your machine to identify this IP address to this MAC address
4. $ ping 192.168.1.X -s 113
   PING 192.168.1.X (192.168.1.X): 113 data bytes
   Request timeout for icmp_seq 0
   Request timeout for icmp_seq 1
   121 bytes from 192.168.1.X: icmp_seq=2 ttl=255 time=418.963 ms
   121 bytes from 192.168.1.X: icmp_seq=3 ttl=255 time=0.958 ms
   •this confirms MAC and IP are linked
5. telnet or www into the PDU(still directly attached) make changes to the IP config, and perform a reboot on the PDU

Voila!